In the past, there has been great emphasis on methods and compositions relating to the inhibition of unwanted hair growth in humans. In particular, for cosmetic reasons it is desirable to remove unwanted hair from parts of the body such as the legs, armpits and face without recourse to shaving.
The products that are currently available for topical use in the removal of unwanted hair are mostly based on thioglycollates as the active ingredient. Examples of products containing thioglycollates are available under the trade names "VEET" and "NAIR". Thioglycollates function as reducing agents at high pH by reducing disulfide bonds in hair. Following penetration into the follicular canal. the hair is weakened in the region above the keratinizing zone. The hair shaft may then be broken off just below the skin surface leaving a soft, smooth skin surface.
Hair growth does not however cease and, since the hair is broken near the surface, regrowth occurs within a relatively short time and the cosmetic advantage is thus rapidly lost. Retreatment with the thioglycollate product is necessary if the treated skin is to be maintained in a hairless condition. There is consumer resistance to the continual use of thioglycollate hair removal product as skill irritation is sometimes encountered. However, as no alternative methods of hair removal exist apart from shaving and plucking (including the use of tweezers, forceps and waxing) of individual hairs, in the past thioglycollate-containing products have offered the most effective method. particularly for women, for the removal of unwanted hair from the body surface.
The present inventors have surprisingly found a method and a composition which when applied topically to the skin retards or prevents hair growth. The inventors have found that the method and composition cause the hair growth to be finer, thinner, shorter and much less visible. Typically, coarse hair is replaced by vellus hair. With repeated application the inventors of the present invention have found that hair growth may be prevented entirely.